1. Field of the Invention
This invention relates to an apparatus for applying or installing curable materials into or on a substrate which, after installation, self-cure in situ. More particularly this invention relates to a hand held, powder driven dispensing device or application tool for converting materials of elastomeric content, which are multi-component compositions, preferably in the form of an integrated body of elongated tube, rope or tape-like structure of the discrete parts, into an in situ curable mass.
Excellent examples of the types of materials to be used and dispensed by the apparatus of the present invention are, in general, in a tube, strip, ribbon, cable or rope like form, substantially round in cross section and which, in a preferred embodiment, has an outer shell of uncured, though curable, polymeric material such as a polysulfide polymer containing suitable fillers and the like to give it body and solidity and being capable of extrusion through a suitable extrusion die selected for use for the purpose by skilled artisans and well known in the art. An inner shell is often used of a similarly constituted uncured polymer, and an inner core containing a curing agent, usually in liquid, slurry, or paste like is contained therein. This article is obtained by extrusion, as stated above in a process well known in the art of plastics manufacture and is exemplified and described in U.S. Pat. No. 3,440,309 and also in the 1963 issue of "Modern Plastics Encyclopedia" at pages 744 through 748 thereof, and many other patents and publications. In these uses the extruder by means of its appropriately designed die system can extrude, simutaneously, the double rolled rope, tube or cable-like article described above and fill the inner core of the inner shell with curing agent by means of a suitable metering device and injection nozzle incorporated therewith. The article when extruded is coiled up on a reel and supplied to sealant installers and is capable of being stored for extended periods prior to being converted to a curable polymeric system in a substrate such as for example, the frame of a windshield of an automobile body, or other applications in the construction, aircraft and marine industries to bond together or seal such substrates as, among others, metals, glass, concrete and wood. In the usual application it is desirable to have a curable substance to seal such substrates which will cure after being applied and yet can easily be handled. The subject of the present application is a portable, hand held, device, apparatus or application tool whereby the material discussed above is converted from a storable, curable composition of discrete parts including polymer and curing agent to a composition which is curable in situ after being fragmentized in the application tool and mixed therein in the same apparatus.
2. Description of the Prior Art
In U.S. Pat. No. 3,750,905 to Norman S. Wolfrom is disclosed a hand held thermoplastic sealant extrusion device wherein the material to be extruded and thereafter laid in the substrate is in the form of a heat meltable thermoplastic requiring no mixing. Accordingly in this patent the material is fed into one end of rotatable screw containing housing and conveyed to a nozzle, all the while being heated during its transport from the inlet to the nozzle and laid in a substrate. However, the device disclosed in this patent is the usual extrusion device wherein a heat meltable thermoplastic material is fed to a rotating screw through a heat zone and discharged through a nozzle, or orifice at the other end. The device disclosed is not suitable for handling materials such as is intended to be handled by the present apparatus.
Still another device similar to the one discussed above, is disclosed in U.S. Pat. No. 3,604,597 to H. E. Pohl, wherein the hand held, motorized apparatus receives a rod like material of thermoplastic substance and is fed to a heat zone for melting thereof and later extrusion onto a substrate. This device uses a pair of rollers to convey the heat meltable rod-like thermoplastic raw material to a heat zone where it is melted and later discharged through an orifice. This device, as is quite evident could not be readily adapted to handle materials of the type intended in the present invention.
Still another patent, U.S. Pat. No. 3,711,067 to L. Kovacs, discloses a rotating screw and tandemly attached mixing section for handling extrudable thermoplastic materials transporting the same to the tandemly attached mixer and mixing the same homogeneously. Heater means is also provided to melt the discharged product. While it is apparent that this device can receive, fragmentize, convey and convert materials of the type disclosed and intended by applicants for their device it cannot achieve the efficiency of mixing, nor the degree of homogeneity of mixture as will be evident from what follows in the discussion of the present invention.